In this research,the initial concentration of glucose and sodium glutamate,feeding time,feeding formulation of γ-PGA produced by flask-shaking fermentation of Bacillus subtilis GXA-28 using fed batch culture were investigated.The suitable feeding time was 17 h.Feeding formula was as followes:Glucose 20 g /L,glutamic acid 5 g /L,KH2PO40.5 g /L,MgSO40.1g /L.Under optimal feeding conditions,the production of poly-γ-glutamic acid increased to 24.36 g /L,which was 50% higher than that from batch fermentation.Intensity of production increased from 0.74 g /(L·h) to 0.87 g /(L·h).The results showed that the fed-batch fermentation strategies had a significant effect on the production of γ-poly glutamate and gave a reference for γ-PGA pilot study.